Actually, i think the gas prices were even a bit higher, when they first cancelled the book studies. Based on that logic, since the gas prices are even cheaper now, why havent they reintroduced it?
Personally, i think the WTS realised that they were getting "nothing" out of the book study arrangement. There were no contribution boxes at the home book studies, that 90 % of the congregation went to. So the WTS probably figures, instead of having the R&F "waste" ANY money going to the book study, where there is NO chance of money going into a contribution box, they would cancel it, and have the R&F "save" that money, so it has a better chance of going into a contribution box in the Kingdom halls.
Its funny, too, how it used to be part of someones "reinstatement process", that they attended ALL the meetings that they could, to "measure spirituality". The Elders would say, "you should go to the Sunday meeting, the weekly ministry school meeting, AND even the BOOK STUDY that was held at the Kingdom hall. This, in the Elders eyes, showed how much you REALLY cared about being spiritual, and reinstated. Then one day, they just completely do away with the weekly book study. YET, that meeting used to be a "barometer" for spirituality/reinstatement.
AND, why in these "last days", when things should be ramping up, and our spiritual "food" should be increasing, and more important, would they completely do away with MORE spiritual food. I guarantee, cause it did NOT increase the WTS "revenues". It was an "unneccessary" meeting to the GB, and didnt fill the contribution boxes. It shows what they REALLY care about, and it is NOT the flocks spirituality, thats evident.